Gelignite and gelatin dynamite



Patented Oct. 21, 1930 UNITED STATES PATENT OFFICE BOY LINDEN BILL, OFWILMINGTON, DELAWARE, ASSIGNORTO ATLAS POWDER GOM- IPANY, OF WILMINGTON,DELAWARE, A CORPORATION OF DELAWARE' GELIGNI'IE AN D GELATIN DYNAMITE1V0 Drawing.

The objects of my invention are to provide gelignites and gelatindynamites of such composition that they will possess improved softnessand plasticity, better keeping qualities 5 in storage, higherpropagation sensitiveness,

and greater assurance of high rates of detonation than have heretoforebeen readily possible with known products of this nature.

My invention further contemplates the in provision of gelignites andgelatin dynamites that are more easily and economically handled inmanufacturing operations than has heretofore been possible.

An additional feature of novelty and advantage resides in the fact thatby the present invention I can more readily prepare satisfactoryexplosives of the types mentioned, with a lower nitroglycerin contentthan heretofore.

Broadly stated, the invention resides in the introduction of What I havechosen to call .pelleted sodium nitrate or pelleted potassium nitrateinto the explosives concerned. To avoid any misinterpretation I maydefine my meaning as follows, using sodium nitrate as the example:

I am concerned with sodium nitrate which exists in the form of sphericalor semi-spherical particles such as would be formed by submitting themolten material to shot towers or ejecting it through a spray gun bymeans of air or gas pressure. It is so special and peculiar in form thateven a casual observation would indicate that it could not be formed byany grinding treatment of coarse sodium nitrate, or by any of theestablished methods of preparing this salt for use in explosives.Fortunately, for some of the objects of my invention many or all of thepellets are hollow to a greater or less extent. I place no limit of sizeon the spherical or semi-spherical particles. They may be so small thatall will pass a 100 mesh screen or as large as conditions of applicationrender desirable.

I have also found that potassium nitrate, pelleted into similarspherical or semispherical particles, exerts an advantage, similar tothat of pelleted sodium nitrate, in gelignites and gelatin dynamites,and it is to be Application filed December 14, 1928. Serial No. 826,154.

understood that the use of this material constitutes a phase of myinvention.

It is not necessary to use either pelleted sodium nitrate or pelletedpotassium nitrate, as the entire content of these salts in my gelignitesor gelatin dynamites. My compositions may include a. proportion ofeither one of these salts prepared in any well known way as by grinding,but, when using either of the pelleted salts, atleast five percent ofthe total content of such salts will be in the pelleted condition,because lesser amounts do not provide suificientl advantageousconditions.

There shoul be no misinterpretation of the meaning of gelignites andgelatin dynamites by those skilled in the art. They are explosives whoseconsistency has been effected by the use of more or less nitratedcellulose which has an appreciable degree of solubility innitroglycerin.

Three examples will be given as follows, but it should be understoodthat I do not confine myself to these examples and that my inventioncovers the entire field of gelignites and gelatin dynamites in whichpotassium nitrate or sodium nitrate are used.

Example N o. 1

Per cent Nitroglyoerin 42 Nitrocottonuns 1 Pelleted sodium nitrate"; 45Wood meal 5 Flour 6 Chalk 1 Example N o. 2

Per cent Nitroglycerin 51 Nitrocotton 2 Pelleted sodium nitrate 25Ground sodium nitrate 12 Wood pulp 9 Chalk 1 Example N o. 3

Per cent Nitroglycerin 18 Nitrocotton 0.4 Pelleted potassium nitrate 50Ground potassium nitrate 15 Flour l1 Sulphur 4.6 Zinc oxide 1 Theadvantages of the invention will be better appreciated after aconsideration of the following facts: It is known that practically anyexplosive may be dead pressed, that is, pressed to a point where it willeither detonate with a low order of detonation or merely burn. Obviouslyincreased pressure means less or no air spaces between the particles.With this condition it is assumed that the failure of explosives tofunction properly when over-pressed is probably connected. A geligniteor gelatin dynamite may be looked upon as a honey comb of minute airparticles surrounded by films of colloided nitro-cellulose. Byinsufiicient stirring in of air during mixing over pressing in packing,or submission to a series of temperature changes, the explosives notedare known to deteriorate in the properties mentioned. It is assumed thatthis is due to loss of aeration or the collapse of the minute air cells.Density increases during deterioration also point toward this.

Obviously, spherical or semi-spherical particles will not pack like afine powder or irregular particles, and automatically provide sturdywalled air spaces in the explosives. The hollow nature of the pelletsfurther provides such a condition. The result is an aeration of theexplosives which is maintained under very severe conditions andexcellent keeping qualities are effected. Since the explosivesmanufactured in accordance with this invention represent the greatestdeparture from the dead pressed phenomena they will detonate withmaximum orders of detonation and so show excellent propagationsensitiveness and-rate of detonation conditions. Their resistance toloss of aeration will also keep them most effective in use underconditions of hard tamping and high pressure, as in deep holes filledwith water. There is actually provided a new form of aeration to augmentthe aeration caused by stirring air into the colloided nitrocellulose.

The spherical or semi-spherical particles will roll readily within themass of gelatin, as compared with fine powder or irregularly shapedparticles. This tends toward easier packing into cartridges and greaterconditions of softness and plasticity. Easier packing into cartridgesmeans less pressure exerted and less loss of aeration, showing theinterlocking nature of the effects.

Also the spherical or semi-spherical particles, most of which have noopening into the hollow interior, present less surface to whichnitroglycerin may adhere, as compared to particles of other shapes andfine powders. Thig obviously presents the possibility of preparingmoist, soft, plastic masses of gelatin with less nitroglycerin thanusual. There is thus rendered possible the manufacture of lowerstrength, cheaper gelatinous explosives,

arrears for which there is acbroad demand among consumers.

My experience, derived from extended experimentation, has demonstratedthat explosives prepared as described herein possess better keepingqualities, higher propagation sensitiveness, higher rates of detonationand greater softness and plasticity than explosives made with ordinaryground sodium nitrate, and that such explosives maybe more easily andeconomically manufactured, and may be made with a lower nitroglycerinecontent in the production of a good gelatinized mass, than has beenpossible by any method of manufacture heretofore practiced. F urther, byvirtue of the use of the im roved sodium nitrate in pelleted form, aserein-' before described, I am able to secure increased densities ingelignites and gelatin dynamites, without corresponding decrease ofaeration. I wish to specifically disclaim the use of ammonium nitrate inpelleted form of the nature of that disclosed in the patent to Symmes,No. 1,613,335, because such ammonium nitrate yields a lower density thaneven ordinary granular ammonium nitrate or Chilean sodium nitrate. 3

Lower density is desirable in those explo sives of the permissible typewhile gelatin dynamites and gelignites from the very nature of their aplication require a high density. The intro notion of ethylene glycoldinitrate in the manufacture of dynamites has tended to reduce theirdensity and has been a source of worry and trouble to explosivemanufacturers. Consequently, thing tending to further lower theirdensityis to be avoided.

It, is understood that the invention applies only to gelatinous exlosives, commonly nown as gelignites an gelatin dynamites. They are verydifferent from non-gelatinous dynamites in structure and in the effectsof various conditions upon them.

It is further to be understood that the invention is not limited to theparticular proportions recited, but that it includes within lts purviewany composition coming within either the terms or the spirit of theappended claims.

Having thus clearly set forth theessential features of the invention,and shown by example how it may be applied, I claim: Y

1. Pelleted alkali metal nitrate in geli n1tes and gelatin dynamites asherein (1%- scribed. i

' 2. Alkali metal nitrate in particles of sub,- stantially sphericalform in gelignites and gelatin ynamites. I

3. Gelignites and gelatin dynamites which contain substantiallyspherical particles of sodium nitrate.

4. Gelatinous explosives which, contain al-' kali metal nitrate whichhas been converted to a spherical form from a molten condition.

any-

its

5. A gelatinous explosive containing an alkali metal nitrate inparticles of substantially spherical form.

6. A gelatinous explosive containing an alkali metal nitrate in the formof distinct pellets.

7. A gelatinous explosive containing an alkali metal nitrate in the formof hollow pellets.

8. A gelatinous explosive containing substantially spherical pellets ofsodium nitrate. 9. A'gelatinous explosive containing hollow pellets ofsodium nitrate.

10. A gelatinous explosive containing hol- 15. low pellets of an alkalimetal nitrate of substantially spherical form.

11. A gelatinous explosive of greatly increased aerationcharacteristics, having as an ingredient thereof substantially sphericalhollow pellets of sodium nitrate.

12. A gelatinous explosive of greatly increased, aerationcharacteristics, having as an ingredient thereof substantially sphericalhollow pellets of sodium nitrate in the form produced by dischargingmolten sodium nitrate into the atmosphere.

In testimony whereof I aflix my signature.

ROY LINDEN HILL.

